182results about How to "Meet the test" patented technology

The invention discloses a method and a system for automatically testing the relay protection function of an intelligent substation. The simulation system of the entire substation is realized in the mode that a simulation host machine is used for controlling digital relay protection and testing devices, a testing environment is provided, closed-loop testing on intelligent equipment is performed, the intelligent equipment with any scale of the substation can be tested in the mode that the simulation host machine is connected with the digital relay protection and testing devices, when tested equipment is added and the existing simulation system cannot meet the testing scale, the relay protection and testing devices in cascade connection are added to meet the testing requirement for intelligent equipment with larger scale, and besides, testing for a plurality of intelligent equipment can be realized, and the application prospect is better.

The invention provides an on-site level radio testing system and a method thereof for the network debugging application of underwater sound sensors, which relate to the field of system tests. A backbone network of the testing system is built on the basis of a radio-frequency radio communication mode and comprises a trunk node (1) which simultaneously supports radio-frequency communication and wired communication, a convergent node (2) and a system administrative center (3) which simultaneously support the radio-frequency communication and the wired communication, and the trunk node (1) provides a wired communication interface for the communication of underwater sound communication testing nodes. The method comprises a uniform transmission mode of automatic framing data packets in different transmission agent, and a TDMA-based two-way transmission method of water surface radio-frequency radio communication. The method can be widely applied to tests in aspects, such as the study of algorism for processing signals of underwater communication systems and the study of the network communication protocol of underwater sound sensors.

An actuator performance tester comprises a measurement and control console and an electric loading platform, which are connected through cables; the measurement and control console comprises a display, a printer, a signal conditioning case, an industrial personal computer, a program-controlled current source case, a power distribution case, a scram control box, a mouse and keyboard suite, a lower computer case and a rack; the electric loading platform comprises a position encoder, a flexible connecting plate, two bearing caps, two swivel bearings, two shaft system supports, a rocker, a transmission shaft, a torque / rotational speed sensor, a motor support, a torque motor, a bed, two couplings and a fixture. The actuator performance tester can carry out static and dynamic performance tests on a universal gas actuator in order to obtain the performance of the actuator in real time, and can store and manage performance data.

The invention provides a fish swimming capability measuring method and a submerged open-type measuring device. The method includes 1, making preparation before experiments; 2, testing and correcting systems; 3, testing swimming capabilities of fishes; 4, collecting experiment data; and 5, maintaining and cleaning the systems. A water outlet tube with a water level adjusting device is mounted at the bottom of a water tank of the submerged open-type testing device. A support, an experiment table base, a stabilizing cove and a testing tube are mounted in the water tank. A water current creating system formed by a motor, a water inlet hole and a vane wheel is arranged at one end of the testing tube. The water current creating system and a test area with an inspection window are respectively connected with two ends of a rectifying device. The test area with the inspection window is connected with a flow rate test area. A current meter is mounted in the flow rate test area connected with a water level control area. A water current flow rate monitor, a frequency conversion controller and a water quality monitor are mounted on a control panel. A water inlet tube is mounted at one end of the upper portion of the water tank.

The invention discloses a high-power pulse current / voltage generating circuit with programmable pulse width, duty ratio and pulse amplitude, wherein a digital-analog converter, an error amplifier, a power amplifier, a pulse current sampling circuit, a pulse voltage sampling circuit, a pulse current / voltage sampling selection switch and a peak detecting circuit are formed into a negative feedback loop. The amplitude analog signal output by the digital-analog converter is compared with the pulse peak obtained by the peak detecting circuit in the error amplifier; and the pulse peak is equal to the amplitude analog signal output by the digital-analog converter in the negative feedback loop. The power amplifier is connected with the output end of the comparator and is connected with the output end of the error amplifier through an input resistor; the comparator adjusts the frequency and duty ratio of the output high-power current / voltage under the control of the periodic pulse signal output by the pulse source, thus, the pulse width, the duty ratio and the pulse amplitude of the output pulse current / voltage of the high-power pulse current / voltage generating circuit can be adjusted.

The invention relates to a low-loss large-effective-area fiber and a preparation technology therefor. The low-loss large-effective-area fiber comprises a core layer, wrapping layers and coating layers from inside to outside in sequence. The core layer is a pure silica glass layer with the radius of 5-7 [mu]m. An inner wrapping layer is a fluorine-doped inner wrapping layer with the radius r2 of 5-12 [mu]m and the relative refractive index difference of from -0.4% to -0.2%. The radius r3 of a middle wrapping layer is 12-25 [mu]m. An outer layer is a pure quartz glass layer with the radius r4 of 25-45 [mu]m. The coating layers adopt polyacrylate and comprise an inner coating layer and an outer coating layer, the diameter of the inner coating layer is 192 [mu]m, and the diameter of the outer coating layer is 245 [mu]m. The preparation technology comprises a perform rod preparation process, a fiber fusion annealing process and a fiber drawing and curing process. The fiber provided by the invention is advantaged in that comprehensive properties such as cut-off wavelength, bending loss and dispersion are good in an application waveband; the fiber can be used in long-distance fiber communication by crossing bad conditions of gobi, deep sea and the like; the roundness of each layer of the fiber is good, so that the appearance is enabled to be round; and the strain of the fiber can reach 2% or more.

The invention discloses a steam generator test system, which comprises a shell, a lower assembly, an upper assembly, a supporting assembly and an operation platform, wherein the top part and the middle part of the shell are respectively provided with a steam outlet nozzle and a water supply inlet, and the bottom part is provided with a coolant inlet and a coolant outlet; the lower assembly comprises a heat transfer tube arranged in the shell and a tube bundle sleeve arranged outside the heat transfer tube, two ends of the heat transfer tube are respectively communicated with the coolant inlet and the coolant outlet, and the tube bundle sleeve separates the shell into a falling channel and a rising channel communicated; the upper assembly comprises a water supply loop tube, a steam-water separator and a drier sequentially arranged above the tube bundle sleeve, and the water supply loop tube is communicated with the water supply inlet; the supporting assembly is fixedly connected onto the bottom part of the shell for supporting the shell; and the operation platform is arranged outside the shell for training and operation. The test system can meet demands on special tool development and test and personnel training, skill proficiency of a maintenance person can be ensured, and damage to the steam generator or person radiation pollution in the case of actual operation can be avoided.

The invention relates to a high-precision RV speed reducer comprehensive testing device, which comprises a base, a first sliding platform, a second sliding platform, a first motor, a first torque sensor, a second motor, a second torque sensor, a first angle sensor, an input shaft bracket and an output shaft bracket. Compared with the prior art, the high-precision RV speed reducer comprehensive testing device designs the sliding platform assembly capable of being rapidly disassembled and assembled, so that the assembling and disassembling process of an to-be-tested RV speed reducer is more convenient and faster; the output shaft bracket and the input shaft bracket can be used for adapting to the requirements of sensors with different specifications; the limiting parts of the sliding platforms improve the test precision; the double-measuring-range torque sensors can adapt to measurement of speed reducers of different series models, and can also realize test of transmission precision under light load; an input shaft of the to-be-tested RV speed reducer is installed in two bearing inner rings sharing the same horizontal axis, thereby facilitating the adjustment of a bearing clearance;and the double-reading-head circular grating angle sensors meet the requirement that the transmission precision is tested in a high-speed state.

The invention discloses a field-programmable gate array testing method and belongs to integrated circuit design in the field of microelectronics and the field of electronic design automation. The method includes generating a testing circuit file according to a field-programmable gate array chip structure; generating a testing circuit constraint file according to the field-programmable gate array chip structure; obtaining an integrated net list according to the testing circuit constraint file; obtaining a mapping circuit net list according to the testing circuit constraint file and the integrated net list; completing routing of the testing circuit file according to a post-layout circuit unit and the testing circuit constraint file; obtaining a code stream file; testing an FPGA chip according to the code stream file. According to the field-programmable gate array testing method, the testing circuit is subjected to integration, mapping, layout, routing and code stream generation under constraint of the circuit constraint file, and the code stream file required by verification and testing is generated. The field-programmable gate array testing method is capable of effectively achieving wafer testing after FPGA layout verification and tape-out.

The invention belongs to a high-voltage wiring harness conductivity automatic-testing device of an electric vehicle. High-voltage connector assemblies of the device are connected with high-voltage wiring harnesses. The high-voltage wiring harnesses are connected with a relay matrix through respective adapter wiring harnesses, and the relay matrix is controlled through an I / O port of a single chip microcomputer. A voltage value output by an A / D reading acquisition circuit inside the single chip microcomputer is utilized to judge the conductivity of terminals of the high-voltage connector assemblies of the high-voltage wiring harnesses according to an A / D acquisition value. The high-voltage wiring harness conductivity automatic-testing device is high in time response, small in size and low in power consumption and ensures test signal accuracy and the safety of testers while achieving functions. The high-voltage wiring harness conductivity automatic-testing device can judge the conductivity situation of the high-voltage connector assembly of the high-voltage wiring harness quickly, accurately and really, conductivity testing of the high-voltage connector assemblies of different high-voltage wiring harnesses can be completed only by designing corresponding adapter wiring harnesses on the basis that testing circuit board design is not changed, the device has the advantage of being high in universality, and the problem that the conductivity testing of the high-voltage connector assemblies of the high-voltage wiring harnesses is difficult is successively solved.

The invention belongs to a device for automatically testing continuity of a high-voltage connector of an electromobile high-voltage control box. The device comprises a through-connection wire harness, a relay matrix, a collection circuit, a single chip microcomputer, a testing button, an LCD (liquid crystal display) and a power source circuit. During testing, after a connector of the through-connection wire harness is accurately connected with the connector of the high-voltage control box to be tested and a power source works, testing can be performed by only pressing the testing button down. Connecting wire harness continuity testing in the high-voltage control box includes anode connecting wire harness continuity testing and cathode connecting wire harness continuity testing. All relays in the device are PhotoMOS relays, so that testing speed is increased greatly. The device can judge continuity conditions of the high-voltage connector of the high-voltage box quickly, accurately and truly and has the advantage of high universality, and the problem of difficulty in continuity testing of the high-voltage connector of the high-voltage control box is solved successfully. The whole device is simple in design, high in performance reliability, few in electronic device, low in cost and high in practicability.

An apparatus for measuring soil permeability coefficient comprises one open tubular column; the open tubular column comprises a top half and a bottom half, which are connected by a flange; the bottom of the open tubular column is provided with be provided with a bedding layer; the upper portion of the bedding layer is provided with a soil filling layer; the top half of the open tubular column is provided with at least one drain pipe; the drain pipe is provided with a valve, and connected with a water tank; the top half of the open tubular column is provided inside with a water inlet pipe connected with the water tank; the water inlet pipe is provided with a diaphragm water pump; the open tubular column sidewall at the terminal of the soil filling layer is provided with a first piezometer tube; the open tubular column sidewall at the top of the soil filling layer is provided with a second piezometer tube; and the open tubular column sidewall of the bedding layer is provided with a water outlet pipe. The apparatus provided by the invention can measure soil permeability coefficient under constant water head difference, or variable water head difference, has advantages of simple structure, convenience for operation, wide scope of usage and good accuracy.

The invention discloses an iron roughneck makeup-breakout torque testing method. The method comprises steps: a hydraulic pressure control mechanism connected with the iron roughneck is started, the iron roughneck is operated to adjust the position of each clamp body assembly of the iron roughneck, the back-up wrench of the iron roughneck clamps a lower simulation drilling tool, a clamping clamp or a fastening clamp of the iron roughneck clamps an upper simulation drilling tool, and torque test is chosen to be carried out on the clamping clamp or on the fastening clamp according to test demands; a static torque sensor transmits data signals to a data acquisition mechanism in real time, and the data acquisition mechanism stores and displays a well-processed torque value; and in the case of test, the back-up wrench clamps the lower simulation drilling tool, the clamping clamp is rotated to obtain a torque value which is the torque value of the clamping clamp of the iron roughneck, and the fastening clamp is rotated to obtain a torque value which is the torque value of the fastening clamp of the iron roughneck, and the test is completed. By using the method of the invention, the actually-outputted makeup-breakout torque values when the iron roughneck operates can be accurately tested.

An air bleeding pipe joint has a pair of connection pipe portions, a branch pipe portion having an air bleeding hole in an inside thereof, a plug body, and an elastic annular sealing member providing an air-tight seal between a female fitting surface of the branch pipe portion and a male fitting surface of the plug body. The plug body is removably mounted to the branch pipe portion in threaded engagement therewith such that a seating surface of the plug body seats on a seated surface of the branch pipe portion. An air discharge path is provided on an upper end of the branch pipe portion and / or the plug body with respect to a sealing position at which the sealing member is disposed for discharging outwardly an air that leaks upwardly through the sealing position.

The invention discloses an electric locking and unlocking mechanism which comprises a direct-current electromagnet, a moving mechanism, a spring, a threaded pressing block and an unfolded test plate. The moving mechanism and the direct-current electromagnet are mounted on two parallel and opposite sides of the unfolded test plate provided with a through hole through a guide sleeve respectively, a sliding sleeve is in threaded connection with an armature of the direct-current electromagnet on the other side through the through hole of the unfolded test plate, and the sliding sleeve is coaxial with the through hole of the unfolded test plate; the threaded pressing block mounted in the through hole of the unfolded test plate through a thread presses the spring on the sliding sleeve, the sliding sleeve receives pressure of the spring axially to clamp locking balls in ball holes of a ball frame, and the locking balls are fitted with a groove of a locking bolt to lock the locking bolt; a display system with a locking hole can be locked on the locking bolt by a locking nut. The direct-current electromagnet is selected as power, electric signals are taken as switch signals, uniform and accurate control on a test experiment of the display system can be realized through the electric locking and unlocking mechanism, and data collected by testing are accurate and reliable.

The invention discloses a testing method of simultaneous rotation of inner and outer rings of a cylindrical roller bearing; the testing device comprises a substrate, an inner ring revolving system arranged at the upper part to drive a testing bearing to rotate and an outer ring revolving system; the outer ring revolving system comprises an outer ring main shaft, an accompanied testing bearing, an axial force applying bearing and a supporting bearing are sleeved on the outer ring main shaft; the inner ring revolving system comprises an inner ring main shaft, and an axial force applying bearing, the supporting bearing and a radial loading bearing are sleeved on the inner ring main shaft; outsides of two axial force applying bearings are provided with axial force applying devices; the upper part of the radial loading bearing is provided with a radial loading device; the upper part of the accompanied testing bearing is provided with a sensor unit; the testing device further comprises a lubricating system and a measuring and control device; the axial force applying device, the radial loading device and the lubricating system are connected with the measuring and control device. The invention provides a testing method of the simultaneous rotation of inner and outer rings of the cylindrical roller bearing; the method applies the method of rotating the inner and outer rings at the same time, and thus the testing rotate speed can be effectively improved.

The invention discloses a device and a method for testing the wet expansion coefficient of a carbon fiber composite material. The main body of the device adopts a thermal mechanical analyzer (TMA), the device is improved based on the TMA and equipped with a set of humidity controller for controlling humidity precision, the humidity controller comprises a water steam boiler and a humidity sensor, and the humidity control range is within 5-100 percent; within a certain humidity range, a wet deformation test is performed by using a displacement sensor and a mechanical sensor of the TMA. The device for testing the wet deformation has the characteristics of high testing speed, wide testing range, high resolution ratio and the like, and the requirement for the wet deformation test of various composite materials can be satisfied.

The invention discloses an Android mobile phone automatic testing system. The Android mobile phone automatic testing system includes an interface layer calling module used for calling the function of a mobile phone interface layer, and a testing module used for testing the function of the mobile phone interface layer through the interface layer calling module and automatically generating a testing report. The invention further discloses an Android mobile phone automatic testing method. The automatic testing method includes the following steps: an Android mobile phone is connected to an assistant device for testing; the interface layer calling module and the testing module are installed on the Android mobile phone through the assistant device for testing; the testing module calls the function of the mobile phone interface layer of the Android mobile phone through the interface layer calling module to test and automatically generates the testing report. The Android mobile phone automatic testing system and the method thereof are not existed with any limit about brand and system version of the mobile phone, so that the tool can satisfy the diversified mobile phone testing.

The invention relates to a PLC technology-based signal simulation driving system and application thereof. The system is connected with a rail traffic signal system. The signal simulation driving system comprises an FEP server, a PLC and simulation console. The simulation console comprises a driver controller, a human-machine interaction interface DMI, a virtual train control screen and a route map display screen, wherein the driver controller, the human-machine interaction interface DMI and the virtual train control screen are connected with the PLC; the PLC and the route map display screen are connected with the FEP server; the FEP server is connected with the rail traffic signal system. The system can save costs, time and space.

The invention provides an experiment device and a method of a rainfall side slope model under lateral non-uniform loading conditions. The experiment device comprises a model box, a lateral non-uniform loading system and a rainfall system, wherein the lateral non-uniform loading system is arranged on the left side of the model box; the rainfall system is arranged at the top of the model box; the lower end of a pressing plate in the lateral non-uniform loading system is hinged to the bottom of the model box; the left side of the upper end of the pressing plate is hinged to an oil cylinder piston which is mounted on an oil cylinder support base; under the action that a piston is pushed by hydraulic equipment to move, the pressing plate can be controlled to rotate around a connecting rod support base at the lower end. By adopting a lateral non-uniform loading mode, the characteristics that an upper part has large displacement and a lower part has small displacement in the deformation process of a side slope are achieved, and actual deformation characteristics of the side slope are relatively really simulated. Through simultaneous rainfall and lateral non-uniform loading simulation, the side slope deformation degree, the infiltration depth and the position of a sliding surface can be tested under different rainfall types and different lateral non-uniform loading conditions. The problems that single external influence factors are available and actual side slope deformation is not met in conventional artificial rainfall simulation tests can be effectively solved.

The invention relates to a test bench, especially to an isolator performance test bench, which belongs to the technical field of isolator performance tests. According to the technical scheme provided by the invention, the isolator performance test bench comprises a bottom plate, a reverse slipping test mechanism and a forward moment test mechanism, wherein the reverse slipping test mechanism is arranged on the bottom plate and can be used for carrying out reverse slipping tests on a starter isolator to be tested; the forward moment test mechanism is arranged on the bottom plate and can be used for carrying out forward moment tests on the starter isolator to be tested; the forward moment test mechanism comprises a forward moment loading device which is used for loading a forward rotary moment on the starter isolator to be tested; and the forward moment loading device comprises a servo motor and a torque sensor used for detecting a forward moment. The isolator performance test bench is compact in structure, can realize reverse slipping tests and forward moment tests, has wide applicable range, is high in test precision, and is safe and reliable.

The invention relates to an electronic load of a semi-passive type programmable simulation LED characteristic. The electronic load comprises an embedded control module, a basic power circuit module, and an LED characteristic simulation circuit module. The LED characteristic simulation circuit module comprises an LED positive volt-ampere characteristic waveform sampling circuit, a high frequency and low frequency alternating current LED volt-ampere characteristic separating circuit, a high frequency variable gain amplification circuit, a low frequency variable gain amplification circuit and a high speed linear drive circuit; the basic power circuit module comprises a high speed power circuit, a high speed low impedance power supply circuit and a read-back sampling circuit. Through adding the LED characteristic simulation circuit module, the embedded control module and a basic power circuit, the electronic load not only can satisfy a test requirement of a common load power supply, but also can simulate a work characteristic of a real LED load, thus tests of all LED driving power supplies and the like are satisfied, and a more accurate and reliable test result is obtained.

The invention relates to a turbocharger test device, in particular to a test stand used for testing self-circulation performance of double turbochargers and provided with a high-pressure gas shunt device. The test stand is characterized in that the gas shunt device is arranged at an outlet end of a gas compressor of a high-flow main turbocharger on a main test stand rack and shunts high-pressure gas compressed by the gas compressor into two pipelines, and gas in one pipeline returns to a main test stand rack combustion chamber through a main turbocharge self-circulation communication valve; gas in the other pipeline passes an auxiliary test stand rack access control valve and drives a low-flow auxiliary turbocharger through an auxiliary test stand rack combustion chamber, and the auxiliary test stand access control valve is switched off after the low-flow auxiliary turbocharger operates stably. According to the test stand, performance testing in an actual state can be simulated really, tests of two different types of turbochargers can be met simultaneously, and the test stand is applied to various operating conditions for test. Besides, the test stand is simple in mechanical structure and easy to adjust, realizes energy conservation and emission reduction, reduces cost and improves the test efficiency.

This invention discloses a kind of double boundary intellect card simulate card which includes a simulate slug, a program memory device. When working the simulate slug fetches the user program in the program memory device by the program among that it also includes the contact interface and the non-contact interface connecting with the simulate slug. The contact interface is a contactor according to the ISO 7816 standard and connects with the contact card reader by the 7816 signal on the contactor; the non-contact interface is a wire similar with the wire in the production card and connects with the wire of non-contact card reader by the carrier signal.

The invention relates to a high-temperature and pressure kettle which is used in optical fibre sensor, it includes a high-pressure autoclave which is in calorstat, a high-pressure metering pump is mounted out of the calorstat, the high-pressure metering pump is connected with high-pressure autoclave via hollow tube, the optical fibre sensor is mounted in the high-pressure autoclave; the hollow tube connected with the optical fibre sensor is also mounted in the high-pressure autoclave, the hollow tube is connected with the outer of the calorstat, the fibre connected with the optical fibre sensor is lead to the outer of the calorstat via the hollow tube. The fibre between several optical fibre sensors is covered with hollow tube; optical fibre ring flange high-pressure protecting house is mounted in the hollow tube. The invention can measure and calibrate the optical fibre sensor in different temperature and pressure safely, test the temperature parameter or pressure parameter of optical fibre temperature or pressure sensor, two- parameter testing can also be done. It is safe, structure is simple, easy to mount and demount.

The invention relates to a dynamic simulator used for a spatial visual navigation sensor and belongs to the technical field of visual navigation of spacecrafts, aiming at solving the problems of high experiment cost and complicated error calibration process of existing dynamic testing methods of visual navigation sensors. The dynamic simulator comprises a high-frequency infrared laser, an optical system, a light source detector optical fiber support, a light source detector optical fiber, an image output device, a linear displacement mechanism, an optical table, a support, a controller and a dynamics computer, wherein the dynamic simulator forms a closed-loop system with the dynamics computer and the visual navigation sensor in a manner of fast assembly to be used for verification of flight control semi-physical simulation experiment; the controller receives data of six degrees of freedom of the aircraft from the dynamics computer, the coordinate of a target on the visual navigation sensor is obtained by calculation with a data processing and control system, and the coordinate of the target on the image output device of the dynamic simulator is obtained by utilizing a mapping relation model. The dynamic simulator is used for visual navigation of spatial visual navigation sensors.

The invention discloses an automatic voltage withstanding capacitance testing machine for a capacitor core. The automatic voltage withstanding capacitance testing machine comprises a detection system,a PLC control system, a host computer, an executing mechanism and an alarm mechanism, wherein the detection system comprises a scanning gun, a core position sensor, a machine origin sensor and a product origin sensor; the executing mechanism comprises a conveying device, core clamping equipment, a cylinder driving unit, a testing module, a servo motor, a voltage withstanding machine and a capacitance tester; guide rails are arranged on both sides of the conveying device; the servo motor drives the testing module to move on the guide rail; the machine origin sensor and the product origin sensor are arranged on the testing module; both the voltage withstanding machine and the capacitance tester are connected with the testing module and PLC control system respectively; and the testing moduleis used for testing the voltage withstanding condition and the capacitance value at a preset position of the capacitor core. The automatic testing of the voltage withstanding capacitance of the capacitor core by the testing machine replaces manual testing of the voltage withstanding capacitance of the capacitor core. The testing machine has the advantages of safety in operation, precise control and high production efficiency.

The invention discloses a rock core capillary self-absorption simulation instrument. The instrument comprises a rock core holder, the rock core holder is connected to a confining pressure pump by a third electric control valve, and a second pressure meter is arranged between the rock core holder and the third electric control valve; one end of the rock core holder is connected to a back pressure value, and the other end of the rock core holder is connected to an intermediate container with scale through a second electric control valve and a fluid flowmeter in order; the intermediate containerwith scale is connected to a pressure apparatus though a first electric control valve, and a first pressure meter is arranged between the intermediate container with scale and the first electric control valve; the first electric control valve, the second electric control valve and the third electric control valve are connected to an apparatus for controlling system as well as acquiring and processing data. The instrument can simulate the capillary self-absorption process under the conditions of overbalance, underbalance, and near-balance of stratum; a computer is used in an experiment processfor realizing processing automation of test and data results, in order to obtain self-absorption speed and intrusion depth and other parameters of capillary, and better simulate self-absorption of rock core.

The invention relates to optical fiber with a large effective area. The mold field diameter of the optical fiber at the 1550 nm position is 12.0-13.6 micrometers, and the mold field area is larger than or equal to 120 square micrometers; the optical fiber sequentially comprises a core layer, cladding layers and coating layers, the core layer is a silicon dioxide glass layer with the radius of 5-7 micrometers, an inner cladding layer is a fluorine-doped inner cladding layer, the relative refringence difference is -0.4--0.2 %, the radius r3 of the middle cladding layer is 12-25 micrometers, and the outer cladding layer is a quartz glass layer with the radius r4 of 25-45 micrometers; the coating layers include an inner coating layer and an outer coating layer, the diameter of the inner coating layer is 192 micrometers, and the diameter of the outer coating layer is 245 micrometers. The cut-off wavelength, the bending loss, chromatic dispersion and other comprehensive performance parameters in the application wave band are good, the optical fiber can be used as long-distance optical fiber communication under bad conditions such as super crossing gobi and deep sea, the circular degree of all layers of the optical fiber is good, the round formed shape is ensured, and strain of the optical fiber can reach 2% or more.